1. Field of the Invention
The present invention relates generally to burnishing devices for hard disks, and more particularly to a burnish head having a plurality of burnishing pads.
2. Description of the Prior Art
A hard disk is cleaned and burnished following the deposition of thin film layers to remove debris and asperities from the surface. Such debris and asperities must be removed, or at least reduced in height, such that a slider will fly smoothly over the disk surface. As slider flying heights become lower for improved higher density disks, the disks must be burnished to a greater extent than was heretofore necessary lower the projection height of such asperities and more efficiently remove disk surface debris.
Several different burnishing pad designs are currently utilized. Some heads have a burnishing ridge providing a burnishing edge that extends across the entire front surface of the head. Other current head designs have burnishing members on the left side and right side of the burnishing head, but have a lengthwise channel between the left and right burnishing members. In such heads, a significant portion of the burnishing head does not burnish the disk, resulting in significant inefficiency in the burnishing process.
A further prior art burnishing head is described in U.S. Pat. No. 4,845,816. It has a waffle type pattern of burnishing pads; that is, a plurality of diamond shaped burnishing pads that are disposed on the burnishing head surface. The diamond shaped pads are oriented such that the point of each diamond shaped pad is directed towards the media to be burnished. In distinction to this pad configuration, burnishing pads of the present invention each have a straight burnishing edge that is directed towards the media to be burnished. In a prior art variation of this waffle patterned head the leading burnishing pads may be triangularly shaped, as are the leading pads of the present invention.
A need therefore exists for improvements in burnishing heads that remove debris and asperities to a greater degree than has been previously necessary. The present invention provides a burnishing head with a plurality of burnishing pads in a unique configuration that accomplishes these results.